Apparatus for annealing strip



y 14, 1940- J. c. WOODSON 2,200,732

AP PARATUS FQR ANNEA'LING STRIP Filed June 12, 19:59 2 Sheets-Sheet 2INVENTOR 17768 C. /4 oaoson Patented May 14, 1940 PATENT OFFICEAPPARATUS FOR ANNEALING STRIP James C. Woodson, Cleveland, Ohio,assignor to Lee Wilson Sales Corporation, Cleveland, Ohio,

a corporation of Ohio Application June 12, 1939, Serial No. 278,661

' i 3 Claims.

This invention relates to annealing apparatus and particularly to anapparatus adapted for the continuous annealing of strip in strand form.

Various types of strip annealing apparatus have been known heretoforebut all those with which I am familiar have been characterized byserious objections. Horizontal tunnel type annealing furnaces, forexample, require a relatively large floor area and supports for thestrip at intervals therealong which-are likely to mar the surface of thematerial being treated.

I have invented a novel strip annealing apparatus which overcomes theaforementioned objections and is characterized by further features ofnovelty and advantage which will become apparent during the followingdetailed description and be particularly pointed out in the appendedclaims. In a preferred form, my invention comprises a pair of verticallydisposed heating chambers located side by side and a cooling chamberhaving a portion overlying the heating chambers and 2. depending portionprovided with heatabsorbing means. The heating chambers are providedwith heat-exchange tubes extending thereinto through the exposed sidewalls and arranged in spaced banks providing a free passage for striptherebetween. The heat-exchange tubes are of the return bend typewhereby they may be fired from and discharge combustion 0 productsat theexposed side of the heating chamber. This embodiment is illustratedinthe accompanying drawings referred to in greater detail hereinafter. Inthe drawings;

Fig. 1 is a view partly in side elevation and partly in section along acentral vertical plane.

showing diagrammatically the annealing apparatus and associatedaccessories;

Fig. 2 is a sectional view taken substantially along the plane of lineIIII of Fig. 1; line I--I of Fig. 2 illustrates the plane on which thesectional portion of Fig. 1 is taken; and

Fig. 3 is a sectional view taken substantially along the plane of lineIIIIII of Fig. 2.

Referring now in detail to the drawings, the

annealing apparatus of my invention is adapted to receive metal strip Ssuch as cold rolled steel from one of a plurality of coilsmounted onsupports H). A welder II is located adjacent the coil supports, forjoining successive coils end so to end. .It will be understood thatafter the strip in one coil has been fully unwound, the end of the nextcoil is brought forward and joined to the trailingend of the precedingcoil. Driven pinch rolls l2 serve to draw the strip from the coil andthrough the welder ll. Thepinch rolls are stopped during the welding ofone coil to the preceding coil.

A mechanical looper l3 comprises a pair of guide rollsl4 mounted on aliftable carriage I5 traveling in vertical guides and urged upward by acounterweight (not shown). The strip is initially led between the rolls[4 and fixed rolls I6. Thereafter the carriage I5 tends to maintain aloop in the strip as indicated in dotted lines, the size of the loopbeing determined by therelative speeds of the strip as it leaves thecoil and enters the heating chamber next to be described. The looperthus provides surplus strip to enable a continuous feed through theheating chambers to be maintained during the interval when it isnecessary to arrest the trailing end of a coil in order to ;;veldthereto the leading and of a succeeding CO1 A furnace I1 is composed ofa pair of heating chambers I 8 and I9 disposed side by side. The wallsof these chambers are builtup of refractory brick within a suitableenclosure 20 composed of steel plate and a structural frame (not shown).The heating chambers have their greatest dimension vertical and haveslots 2| and 22 at the lower and upper ends thereof respectively wherebystripmay be drawn therethrough. Guide sheaves or drums 23 are journaledvbelow the chambers and the strip passes around these drums beforeentering the chambers.

The heating chambers l8 and I9 are maintained at the desired temperatureby heat-exchange tubes 24 disposed therein. The tubes 24 preferably havethe shape of a flat bottle having a contracted neck 25 which is embracedby the exposed side walls 26 of the chambers through which the tubesextend. As shown in Figs. 1 and 2, the tubes 24 are arranged in spacedvertical banks providing a free space therebetween for the passageofstrip.

The tubes 24 have a removable inner end 21 provided with a projectingfoot.28 adapted to seat in one of a plurality of recesses 29 formed inthe inner side walls 30 of the chambers. Refractory slabs 3| aredisposed in the tubes 24, being supported by ribs 32 on the interiorthereof, and defining connectinginward and outward passages 33 and 34for combustion gases.

Each tube 24 has an air-supply pipe 35 extending through the neckthereof. The pipes 35 of the several tubes are supplied with air frommanifolds 36. Each tube 24 also has a fuelsupply pipe 31 and a burner 38disposed coaxially therein, fuel being supplied to the pipes 31 frommanifolds 39. The tubes 24 also have stack portions 40 communicatingwith their outer ends. The heat-exchange tubes 24 described above arealso disclosed and claimed in my co-pending application Ser. No.240,497, filed November 15, 1938.

From the foregoing description; it will be apparent that when-fuel andair are supplied to the pipes 31 and 35 and the mixture ignited as itemerges from the latter, combustion will occur in the. passages 33 and34 and the combustion gases will follow generally the course indicatedbythe arrows, finally emerging through the stack portion 40. The tubes 24are thus heated to radiant temperature and thereby heat the strip S asit moves upwardly between the tube banks.

A cooling chamber 4| has an upper portion 42 overlying the heatingchambers l8 and I9 andprovided with guiding drums or sheaves 43 overwhich the strip passes on emerging from the chambers through theslots22. The cooling chamber 4| and the heating chambers l8 and 19 may besupplied with an atmosphere of nonoxidizing gas from any suitablesource.

The coolingchamber 4| also has 2. depending portion 44 communicatingwith the upper portion 42 and provided with heat-absorbing means such asthe manifolds 45 through which cooling fluid such as water may becirculated.

Guide drums or, sheaves 46 are mounted adjacent the. lower end of thedepending portion removed from the coiler 50 and a new coil started.

It will be apparent from the foregoing that the invention provides apair of annealing lines disposed in close side by side relation, theuncoiler, welder, pinch rolls, tension device and recoiler beingduplicated in each line. The use of a return bend heating tube makes itpossible thus to position the heating chambers closely adjacent eachother, thereby minimizing the amount of 'floor space required andfacilitating inspection of both lines from either side thereof. It willbe understood without further explanation that the tween the coolingmanifolds 46. Instead of recoiling the strip after annealing, it may befed forward continuously in strand form for further processing as byshearing, coating or the like.

Although I have illustrated and described herein but a preferred formand practice of the invention, it will be understood that changes in theconstruction and operation disclosed may be made within the scope of theappende claims.

I claim: LApparatus for annealing strip comprising a verticallyelongated heating furnace substantially rectangular in section, acentral vertical wall dividing said furnace into a pair of chambers,heatexchange tubes arranged in vertically spaced relation in saidchambers, said tubes extending through the sides of said furnace andhaving feet engaging abutments in said central wall, each of said tubesbeing closed at one end and having a reduced neck at the other servingas an outlet for combustion gases, and a burner extending into the bodyof the tube through said neck.

2. Apparatus for annealing strip as defined by claim 1 characterized byeach of said tubes having generally the shape of a flat bottle, with.means therein defining separate entering and return passages forcombustion gases.

3. Apparatus for annealing strip comprising a vertically elongatedheating furnace substantially rectangular in section and having spacedside walls, heat-exchange tubes arranged in vertically spaced relationin said furnace, said tubes extending through one of said side walls andeach having a foot at one end resting on an abutserving as an outlet forcombustion gases, and a burner extending into the body of the tubethrough said neck. v

JAMESC. WOODSON.

